How are elements arranged in periodic table | By atomic number |
What are the rows in periodic table called | periods |
What do elements in the same column have in common | Same amount of electrons in the outer shell |
What are the columns in periodic table called | groups |
Predicting chemical properties | Because elements in the column have same number of electrons in their outer shell, they have similar chemical properties and will react in similar ways |
How was elements sorted before subatomic particles were discovered | By weight |
Newlands periodic table | - First periodic table
- Ordered by weight
- Some elements were placed in inappropriate places |
Mendeleev's periodic table | - realised there are undiscovered elements, so he added gaps to Newlands periodic table
- He predicted the properties of these undiscovered elements |
The modern periodic table | - Looks very similar to Mendeleev's as the discovery of protons and isotopes shows that Mendeleev order elements by atomic number |
Metals in periodic table | - Found on the left as they have few electrons in outer shell
- When they react they lose electrons then form positive ions |
Properties of metals | - High melting and boiling points
- Good conductors of heat and electricity
- They are all solids except from mercury |
Non-metals in periodic table | - Found on the right of periodic table as they have many electrons in their outer shell |
What happens when non-metals react | - Either gain electrons to form negative ions
- Or share electrons to form neutral molecules |
properties of non-metals | - Low melting and boiling point
- Do not conduct electricity or heat |